Data protection method

Abstract

A data protection method applicable in a data storage system is proposed, so that data stored by a user in a plurality of memory units in the data storage system are prevented from being damaged due to damaged memory blocks in two of the memory units corresponding to each other. When reading data from a particular memory unit by a user is unsuccessful, the method reconstructs the data, rewrites the data into an undamaged memory block of the memory unit and delivers the data to the user. Thus, the method achieves the data protection purpose by allowing data to be read successfully through data reconstructing and rewriting, even when two corresponding memory blocks of storage units storing the same data are damaged.

1 . A data protection method applicable in a data storage system, so that data stored by a user in a plurality of storage unit in the data storage system are prevented from being damaged due to damaged memory blocks in two of the storage units corresponding to each other, the method comprising the following steps of: 
 when reading a data from one of the storage units failed, reconstructing the data, rewriting the data into an undamaged memory block of said storage unit and delivering the reconstructed data to the user.    
     
     
         2 . The data protection method as claimed in  claim 1 , wherein the data storage system employs a disk array.  
     
     
         3 . The data protection method as claimed in  claim 2 , wherein the reading of a data includes reading a data from the data storage system under the circumstance of the disk array.  
     
     
         4 . The data protection method as claimed in  claim 2 , wherein the reconstructing of the data is achieved by the disk array.  
     
     
         5 . The data protection method as claimed in  claim 2 , wherein the disk array is a Redundant Array of Independent Disks (RAID).  
     
     
         6 . The data protection method as claimed in  claim 5 , wherein the RAID is one of a RAID 1 or a RAID 5.  
     
     
         7 . The data protection method as claimed in  claim 1 , wherein the rewriting of the data is obtained by a bad sector remapping function.  
     
     
         8 . The data protection method as claimed in  claim 7 , wherein the bad sector remapping function is provided by the storage unit.  
     
     
         9 . The data protection method as claimed in  claim 1  or  2  or  3 , wherein the data storage system is a disk system.  
     
     
         10 . The data protection method as claimed in  claim 1 , wherein the storage units are disks.  
     
     
         11 . The data protection method as claimed in  claim 10 , wherein the memory block is a sector of the disk.  
     
     
         12 . The data protection method as claimed in  claim 1 , wherein if the data cannot be rewritten into the undamaged memory block of the storage unit, indicating that the storage unit has no available memory block for storage, the data storage system outputs a message informing the user that the storage unit is unavailable for the rewrite process and delivers the data to the user.  
     
     
         13 . The data protection method as claimed in  claim 1 , wherein if the data cannot be rewritten into the undamaged memory block of the storage unit, indicating that the rewrite function of the data storage system is unavailable, the data storage system outputs a message informing the user that the rewrite function of the data storage system is unavailable and delivers the data to the user.  
     
     
         14 . The data protection method as claimed in  claim 13 , wherein the rewrite function is a bad sector remapping function.  
     
     
         15 . The data protection method as claimed in  claim 14 , wherein the bad sector remapping function is provided by the data storage unit.  
     
     
         16 . A data protection method applicable in a disk system employing a disk array, so that data stored by a user in a plurality of disks in the disk system are prevented from being damaged due to damaged sectors in two of the disks corresponding to each other, the method comprising the following steps of: 
 (1) determining whether an error is generated for reading one of the data from one of the disks in the disk array, if so, proceed to step (2); else proceed to step (5);    (2) reconstructing the data by the disk array;    (3) writing the data into the disk currently being read and determining whether the write is unsuccessful, if so, proceed to step (4); else proceed to step (5);    (4) informing the user that data cannot be written; and    (5) delivering the data to the user.    
     
     
         17 . The data protection method as claimed in  claim 16 , wherein the disk array is a Redundant Array of Independent Disks (RAID).  
     
     
         18 . The data protection method as claimed in  claim 17 , wherein the RAID is one of a RAID 1 or a RAID 5.  
     
     
         19 . The data protection method as claimed in  claim 16 , wherein the rewriting of the data is obtained by a bad sector remapping function.  
     
     
         20 . The data protection method as claimed in  claim 19 , wherein the bad sector remapping function is provided by the storage unit.  
     
     
         21 . The data protection method as claimed in  claim 16 , wherein the writing of data includes writing data into an undamaged sector of the disk.  
     
     
         22 . The data protection method as claimed in  claim 21 , wherein if the data cannot be rewritten into the undamaged memory block of the storage unit, indicating that the storage unit has no available memory block for storage, the data storage system outputs a message informing the user that the storage unit is unavailable for the rewrite process and delivers the data to the user.  
     
     
         23 . The data protection method as claimed in  claim 21 , wherein if the data cannot be rewritten into the undamaged memory block of the storage unit, indicating that the rewrite function of the data storage system is unavailable, the data storage system outputs a message informing the user that the rewrite function of the data storage system is unavailable and delivers the data to the user.  
     
     
         24 . The data protection method as claimed in  claim 23 , wherein the rewrite function is a bad sector remapping function.  
     
     
         25 . The data protection method as claimed in  claim 24 , wherein the bad sector remapping function is provided by the disk.